21543262101 has 12 divisors (see below), whose sum is σ = 31119755212. Its totient is φ = 14361385536.

The previous prime is 21543262057. The next prime is 21543262127. The reversal of 21543262101 is 10126234512.

21543262101 is a `hidden beast` number, since 2 + 1 + 5 + 4 + 32 + 621 + 0 + 1 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 13573415025 + 7969847076 = 116505^2 + 89274^2 .

It is not a de Polignac number, because 21543262101 - 2⁹ = 21543261589 is a prime.

It is a super-2 number, since 2×21543262101² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21543262151) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 141495 + ... + 251211.

Almost surely, 2^21543262101 is an apocalyptic number.

It is an amenable number.

21543262101 is a deficient number, since it is larger than the sum of its proper divisors (9576493111).

21543262101 is a wasteful number, since it uses less digits than its factorization.

21543262101 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 131540 (or 131537 counting only the distinct ones).

The product of its (nonzero) digits is 2880, while the sum is 27.

Adding to 21543262101 its reverse (10126234512), we get a palindrome (31669496613).

The spelling of 21543262101 in words is "twenty-one billion, five hundred forty-three million, two hundred sixty-two thousand, one hundred one".